多瑙河是一条有许多支流的大型跨界河流。工业污染,市政废水和航运直接或通过支流排入河流。这些排放会对水和沉积物质量产生不利影响,对水生生物构成危险.具有低水溶性的污染物倾向于在悬浮固体中积累,沉积在河床沉积物中。随后,它们在沉积物中的含量代表一个时间积分样本,表明水道中的污染。然而,沉积物中的总浓度并不直接代表对水生生物的暴露风险,因为沉积物中的积累在很大程度上取决于其性质,即有机材料的数量及其组成,这是很难表征为任何天然材料。在规定的基础上提供污染物浓度,2012年在塞尔维亚境内多瑙河段的11个地点收集的表层河床沉积物样品,用具有恒定累积特性的有机硅被动采样器进行了非原位(在实验室中)平衡,采用多比率平衡被动抽样方法。被动采样器中污染物的平衡浓度在时间和空间上相互可比,并且比总沉积物浓度更能衡量生物利用度。被动采样器中转化为等效自由溶解(孔隙)水浓度的吸收与2013年多瑙河联合调查3中进行的地表水被动采样获得的吸收非常吻合。此外,平衡被动采样器PCB浓度,转换为基于脂质的浓度,与几年前在多瑙河采样的鱼类中测量的浓度非常吻合。在11种优先物质中,只有荧蒽在水中超过欧盟EQS,虽然氟蒽和苯[a]芘超过或接近生物群的EQS,和六氯苯。
The Danube River is a large transboundary river with many tributaries. Pollution from industries, municipal wastewater and navigation is discharged into the river directly or via its tributaries. These discharges can adversely contribute to the water and sediment quality, posing a risk to aquatic life. Contaminants with low water solubility tend to accumulate in suspended solids, which deposit in riverbed sediments. Subsequently, their levels in sediment represent a time integrated sample indicating the pollution in the watercourse. However, total concentrations in sediment do not directly represent the exposure risk to aquatic life as accumulation in sediment heavily depends on its properties, i.e. the amount of organic material and its composition, which is difficult to characterize as any natural material. To provide contaminant concentrations on a defined basis, surface layer riverbed sediment samples collected at eleven locations along the Danube stretch in the territory of Serbia in 2012, were ex-situ (in the laboratory) equilibrated with silicone passive samplers of constant accumulative properties, using the multi-ratio equilibrium passive sampling approach. Contaminant\'s equilibrium concentrations in passive samplers are mutually comparable in time and space and are better measure for bioavailability than total sediment concentrations. Uptake in the passive sampler converted to equivalent freely dissolved (pore-) water concentrations agreed well with those obtained from surface water passive sampling carried out within the Joint Danube Survey 3 in 2013. Furthermore, equilibrium passive sampler PCB concentrations, converted to lipid-based concentrations, agreed well with concentrations measured in fish sampled in the Danube several years earlier. Out of eleven priority substances, only fluoranthene exceeded the EU EQS in water, while the EQS for biota was exceeded or approached for fluoranthene and benz[a]pyrene, and hexachlorobenzene.